Surface engineering with ammonium niobium oxalate: A multifunctional strategy to enhance electrochemical performance and thermal stability of Ni-rich cathode materials at 4.5V cutoff potential. (20th January 2022)

• Record Type: Journal Article
• Authors: Wang, Bo; Zhao, Hailei; Cai, Feipeng; Liu, Zhongzhu; Yang, Gai; Qin, Xianzhong; Świerczek, Konrad
• Is Part Of: Electrochimica acta. Volume 403(2022)
• Publication Date: 2022-01-20
• Subjects: Ni-rich layered oxides -- Surface engineering -- Ammonium niobium oxalate -- LiNbO3 -- Lithium-reactive coating; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139636
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Ni-rich layered oxides with high energy density and low costs are among the most promising candidate cathode materials for the next-generation lithium-ion batteries. However, the intrinsic issues of lithium residuals on particle surface and structural degradation with cycling deteriorate the electrochemical performance and cause safety issues. In this work, a facile and scalable Nb-modification strategy is proposed to remove the surface lithium residuals and in situ form Li-ion conductive LiNbO3 on Ni-rich LiNi0.6 Co0.2 Mn0.2 O2 (NCM622) particle surface with small amount of Nb diffusing into surface lattice and doping at Li sites. The surface Nb-modification is performed with water soluble ammonium niobium oxalate by a wet chemistry route. The reconstructed LiNbO3 -coated/Nb-doped hybrid surface structure of NCM622 enables a unique combination of significantly improved cycling stability, superior rate performance and excellent thermal stability. This developed strategy can be applied to modulate the surface chemistry of other Li-containing materials.